Other useful phrases 'Asking politely'
EXAMPLE: Could you tell me... ?
EXAMPLE: I would be grateful if you could ...
EXAMPLE: I would be interested in having more details about...
EXAMPLE: I would like to know if/when/when/...
EXAMPLE: I would like information on...
EXAMPLE: Do you know if...?
Useful phrases 'Making a Complaint'
EXAMPLE: I would like to complain about... (+ noun or -ing)
EXAMPLE: ... is not what I expected/was expecting
EXAMPLE: I am not satisfied with...
EXAMPLE: I would be grateful if my money was refunded / if you could give me a refund
Reference list
Learning English 'FCE Formal Letter' Retrieved from http://www.rubenvalero.com/english/content/fce-formal-letter-or-email
Oxford Living Dictionaries 'Choose the right greeting and sign off'. Retrieved from https://en.oxforddictionaries.com/writing-help/choose-the-right-greeting-and-sign-off
Oxford University Press 'Sample formal letter' ["PDF file] Retrieved from https://oup.useremarkable.com/production/images/uploads/3687/original/uk_sample_formal-letter.pdf